21242212400 has 60 divisors (see below), whose sum is σ = 51081178512. Its totient is φ = 8489099520.

The previous prime is 21242212399. The next prime is 21242212417. The reversal of 21242212400 is 421224212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 423029 + ... + 470571.

Almost surely, 2^21242212400 is an apocalyptic number.

21242212400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21242212400 is an abundant number, since it is smaller than the sum of its proper divisors (29838966112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21242212400 is a wasteful number, since it uses less digits than its factorization.

21242212400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48678 (or 48667 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21242212400 its reverse (421224212), we get a palindrome (21663436612).

The spelling of 21242212400 in words is "twenty-one billion, two hundred forty-two million, two hundred twelve thousand, four hundred".